Starter mechanisms



Feb. 16, 1932. E. R. WHARTON STARTER MECHANISM Filed May 9, 1950Irp/grpEm Y. 5M re.

Patented Feb. 16, 1932 PATENT Fries EDWARD R. W-HABTON, F MEDFORD,MASSACHUSETTS STARTER MECHANISMS Application filed May 9, 1930. SerialNo. 451,000.

My invention relates to starting mechanisms such as are provided forstarting the operation of internal combustion engines, and it has forits object to provide an improved mechanism of this class.

One type of starter mechanism heretofore proposed is constructed withtwo members mounted upon the armature shaft of a starting motor, both ofwhich are movable relative to said armature shaft rotatively andaxially, or longitudinally. One of these members is a conical maleclutch member fitting into a conical socket provided at one end of theother female member, the opposite end of the latter being provided withone or more cam surfaces engaged by one or more studs projecting fromthe armature shaft. The male conical clutch member has compounded withit a spur pinion that is normally'held out of mesh with the driven gearof the engine by means of a spring. When the motor of a startermechanism of this type is started, the stud on the armature shaftoperates through the cam surfaces referred to, to move the two membersaxially on the shaft toward the driven gear of the engine against thepressure of the spring. This axial movement not only carried the pinioninto mesh with the driven engine gear, but it also operated to compressthe spring thereby to cause the latter to force the male conical memberinto clutching engagement with the female or socket member so that thepinion was not only meshed with the driven engine gear, but alsosimultaneously rotated with the armature shaft to start the engine.

My present invention is primarily designed to provide an improvedstarter mechanism of the type just described, and it is hereinembodiedin a starter mechanism of this type having the peculiar featuresof construction and mode of operation set. forth in the followingdescription, the several novel features of the invention beingparticularly pointed out and defined in the claims at the close thereof.

In the accompanying drawings: Figure 1 is a side elevation of a portionof a starter mechanism constructed in accordance with my invention.

Figure 2 shows a portion of the armature shaft together with the twoclutch members mounted thereon, said two members being shown in section.

Figure 3 is a section on line 33 of Figure 1.

Figure 4 is an end elevation of the armature shaft together with some ofthe parts mounted thereon.

Figure 5 is an elevation of one end of the male clutch memberhereinafter described.

Figure 6 is an end view of the female clutch member hereinafterdescribed;

Having reference to the drawings, 1 shows a portion of the usual gearprovided on the fly wheel of the internal combustion engine inconnection with which my improved starter mechanism is employed.

Suitably supported adjacent the engine gear 1 is an electric motor 2whose armature shaft 3 has loosely mounted on it two clutch members 4and 5..- The clutch member 4: is made at one end with a conical endportion or head, 1a to fit into a complementary conical socket 5aprovided at the inner end of the female clutch member 5. V i

At its outer end the female clutch member 5, which is in the form of asleeve, is constructed with two diametrically opposite spiral slots 6,6, each of which is occupied by a stud 7 projecting from the armatureshaft 8, or rather from a collar 8 that is fixed to said shaft by meansof a set screw 9 that is locked, as usual, against accidental looseningby means of a split wire ring 10 occupying an annular groove providedupon the outside of the collar 8. Each spiral slot 6 has two opposedparallel cam side walls 11 and 12.

When the electric motor 2 is started, its armature shaft is driven inthe direction indicated by the arrow and each stud acts against the camside wall 11 of its slot to move the female member axially on thearmature shaft 3 toward the engine gear 1 against the pressure of aspring 18. 1

The male clutch member 4 is also a sleeve surrounding spring 13 andloosely mounted upon the armature shaft, said member being made with adriving pinion 15 which is nor mally just out of mesh with the enginegear 1 as shown in Fig. 1. It will therefore be 1 clear that when theelectric motor is started the inertia of the two clutch members forcesthe studs 7 to act against the cam side walls 11 to shift both clutchmembers toward the engine gear 1 thus moving the pinion 15 into meshwith said engine gear 1 so that the latter is rotated thereby to startthe engine.

The spring 13 abuts at one end against a shoulder 3a on armature shaft 3and at its opposite end against a shoulder on clutch member 4.Therefore, when the armature shaft 3 is started and the two clutchmembers are moved toward the engine gear 1, as described, the spring 13is compressed andwhen the engine has been started and the armature shaft3 is stopped, the spring 13 assisted by the now running engine gear 1restores the clutch members to their normal positions where the pinion15 is just out of mesh with said gear 1.

The conical portion of the male clutch member 4 is provided withlongitudinally disposed ribs 17, each adapted to occupy a shallowlongitudinal groove 18 provided within the socket 5a of the femaleclutch member 5. These ribs 17 and grooves 18 are made round ed,circumferentially, and comparatively shallow.

Thus the two clutch members 4 and 5 are not only frictionally coupledtogether but also are more or less interlocked by the intermeshinggrooves and ribs so that rotative motion is transmitted from the femalemember to the male member through the engagement of opposed shoulders onsaid members, as well as through the frictional adherence resulting fromthe conical shapes of the coacting parts of the two clutch members.

It is a feature of my present invention that the ribs 17 are constitutedby dove-tail cog inserts each forced into position within a longitudinalclove-tail socket 40 provided upon the conical portion of the clutchmember 4.

This construction permits of making the ribs 17 of one material, forexample bronze,

' 11 of each slot 6 is provided with a stop or abutment shoulder 56 bywhich the movement of the two clutch members toward gear 1 is limitedthrough the engagement therewith of the studs 7. If desired, however,the spring 13 may, as heretofore, be constructed so that when pinion 15is fully in mesh with the gear 1 all of the convolutions of said springare closed and therefore the latter may serve as a rigid abutment alsoto limit the movement of the clutch members toward gear 1. This,

however, is not essential when the slots 6 are constructed with the stopshoulders or abutments 5b.

Continued operation and use of a starter mechanism of this typeincluding a spring 13 often, and usually, results in setting said springin a more or less abnormally compressed condition so that it washeretofore possible for the pinion 15 to drift into mesh with the gear 1while the latter was rotating causing grinding noises and injury to themechanism.

To obviate this obj ectionable feature characterizing mechanisms of thistype as heretofore constructed, I have provided a double spiral spring19 whereof one end portion 19a surrounds the female clutch member 5while the opposite end portion 19d surrounds the male clutch member 4.

Between these two end portions the said doublespring 19 is securelyconfined within a socket 20 provided in a flange 21 at the inner end ofthe female clutch member 5. Thus relative rotary and endwise movementbetween female clutch member 5 and the spiral end portion 19a of spring19 is prevented, while relatively rotary movement between the oppositeend portion 19b and the male clutch member 1 is permitted. 7

The free end of the portion 19b of spring19 encircles the intermediateportion of the male clutch member i and abuts an annular shoulderprovided at the inner end of the conical head of said male clutch memberso that it acts yieldingly to hold said male clutch mem her inengagement with the female clutch member 5. Thus if through continueduse the spring 13 becomes set in more less compressed condition, the endportion 19b of the spring 19 will prevent male clutch member 4 fromdrifting into contact wit-h, or dragging upon, the engine gear 1 whilethe latter is rotating.

As illustrated in Fig. 4 the extremity of the end portion 19a of spring19 is associated with one of the studs 7 so as to function as a springlatch which yieldingly holds said stud at the inner end of its slot 6,normally. Thus the female clutch member 5 is prevented from driftingrelatively to stud 7 and toward gear 1 by the latch portion 19a ofspring 19, while the opposite end portion 19b of said spring preventsthe male clutch member 4 from drifting away from the female member 5toward gear 1, as described.

What I claim is:

1. In a starter mechanism, the combination with an engine gear, of adriving shaft; a pair of co-acting clutch members movabl} andtelescopically mounted on said shaft end to end, one of which isprovided with a pinion to co-operate with said gear; a spring mounted onone of said members and engaging the other member to yieldingly holdsaid members against separating; means yieldingly holding said membersnormally in a position its where said pinion is out of engagement withsaid gear, and means connecting the other clutch member with said shaftthrough which the latter acts when started in motion to shift saidmembers axially thereon thereby to move said pinion into engagement withsaid gear and then positively to rotate said last mentioned clutchmember which in turn yieldingly drives said pinion member.

2. In a starter mechanism, the combination with an engine gear, of adriving shaft;

21 pair of co-acting clutch members movably and telescopically mountedon said shaft end to end, one of which is provided with a pinion toco-operate with said gear; a spring yieldingly holding said membersnormally in positions where said pinion is out of engagement with saidgear; other spring means by which said members are yieldingly andnormally held in clutching engagement independently of said firstmentioned spring and by which the other clutch member is yieldingly heldagainst rotation relatively to said shaft while said gear and pinion areout of mesh, and means connecting said other clutch member with saidshaft through which the latter acts when started in motion to shift saidmembers axially thereon thereby to move said pinion into engagement withsaid gear and then positively to rotate said other clutch member whichin turn yieldingly drives said pinion member.

3. In a starter mechanism, the combination with an engine gear, of adriving shaft; a pinion loosely mounted on said shaft; a sleeve looselymounted on said shaft and having driving connection with said pinion,said sleeve being formed with a spiral cam surface; a stud on said shaftengaging said cam surface to shift said sleeve and pinion toward saidgear when said shaft is started in rotation; a spring for yieldinglyurging said pinion and sleeve in the opposite direction and foryieldingly holding the same normally at the limit of their movement awayfrom said gear, and a spring latch on said sleeve engaging said studthereby to yieldingly hold said stud and sleeve against relativerotative displacement while the latter is at the limit of its movementaway from said gear.

Signed by me at Boston, Suffolk County, Massachusetts, this fifth day ofMay, 1930.

EDWARD R. W'HARTON.

